Simultaneous detection of ascorbic acid, dopamine, uric acid and tryptophan with Azure A-interlinked multi-walled carbon nanotube/gold nanoparticles composite modified electrode

Abstract

In this paper, multi-walled carbon nanotube/Azure A/gold nanoparticle composites (Nafion/AuNPs/AzA/MWCNTs) were prepared by binding gold nanoparticles to the surfaces of Azure A-coated carbon nanotubes. Nafion/AuNPs/AzA/MWCNTs based electrochemical sensor was fabricated for the simultaneous determination of ascorbic acid, dopamine, uric acid, and tryptophan. Cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the electrochemical properties of the modified electrodes. The modified electrode showed excellent electrocatalytic activity toward ascorbic acid, dopamine, uric acid, and tryptophan (pH 7.0). The experiment results showed that the linear response range for simultaneous detection of AA, DA, UA and Trp were 300-10,000 lM, 0.5-50 lM, 0.5-50 lM and 1.0-100 lM, respectively, and the detection limits were 16 lM, 0.014 lM, 0.028 lM and 0.56 lM (S/N = 3). The proposed method offers promise for simple, rapid, selective and cost-effective analysis of small biomolecules. The procedure was also applied to the determination of tryptophan in spiked milk samples. ª 2015 Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Palladium supported on polypyrrole/reduced graphene oxide nanoparticles for simultaneous biosensing application of ascorbic acid, dopamine, and uric acid

“…These diseases include gout, kidney disease, Lesch-Nyhan syndrome, and organic acidemia. It is known that high uric acid levels in biological fluids can cause kidney diseases, hyperuricemia, hypertension, and cardiovascular diseases, low levels of UA can cause Wilson's disease, Fanconi syndrome, celiac disease 9,10 .…”

Carbon‐Nanotube‐Based Materials for Electrochemical Sensing of the Neurotransmitter Dopamine

“…In this work, the Nafion/MWCNTs/AzA and AuNPs served as conductive layers, which increased the interfacial electron transfer between the electrode and the analyte. The corresponding linear response range and LOD (signal‐to‐noise ratio (S/N) of 3) were found to be 300–10,000 μM and 16 μM (for AA), 0.5–50 μM and 0.014 μM (for DA), 0.5–50 μM and 0.028 μM (for UA), 1.0–100 μM and 0.56 μM (for Trp) in urine and milk samples by differential pulse voltammetry (DPV) …”

“…The corresponding linear response range and LOD (signal-to-noise ratio (S/N) of 3) were found to be 300-10,000 μM and 16 μM (for AA), 0.5-50 μM and 0.014 μM (for DA), 0.5-50 μM and 0.028 μM (for UA), 1.0-100 μM and 0.56 μM (for Trp) in urine and milk samples by differential pulse voltammetry (DPV). [32] Many capping agents have been reported for stabilizing NPs including dendrimers, surfactants and polymers. [33] AuNPmodified sensors consisting of overoxidized polypyrrole (OPPy) NT arrays have been found to be a useful electrode for DA detection.…”

Application of Fe3O4@SiO2/GO nanocomposite for sensitive and selective electrochemical sensing of tryptophan

“…Therefore, determination of tryptophan is very important in blood and urine sample in these disease. This compound is sometimes added to dietary, food products, pharmaceutical formulas due to the scarcely presence in vegetables [5][6][7][8]. Hence, a simple, fast, selective, sensitive and accurate method for the determination of this analyte is very important.…”